[angelmb]

So I have power going to my MBP -magnetic safe plug light is green- but my toolbar it says my battery is "Not Charging" and current charge is 82% as shown below:



Upon further investigation, which means launching the iStatPro widget nonetheless, I see there is a mention to 'Health' and then to 'Charge',



So, if current charge is indeed 82% why is the battery not charging in order to get the full charge available?, I wondered about the System Preferences Energy settings but fail to see a mention to charge only when % is below than or anything like that…

And… what is the difference between 'Health' and 'Charge' and why would I have to care about it?, my vague guess is 'Health' may be the best % the battery can deliver and 'Charge' is the current value of what is available to deliver, so Health is always going to be > than Charge, right?.

Anyhow, question remains, if the MacBook Pro is plugged, why is the battery not charging?, to plug/unplug the power adaptor doesn't make a difference.

Thanks.

[ghporter]

Health refers to number of cycles and charge current, while charge reflects the percent of the battery's capacity that it holds. Obviously, 82% should NOT also mean "charged." You should probably recalibrate your battery-run the computer on battery only until it shuts itself down, then fully charge it. Since it only indicates one discharge/charge cycle, it's probably just not calibrated and you're getting a faulty indication of charge.

[seanc]

The concerning thing is that your battery thinks it has only ever done 1 charge cycle - either the battery is confused or the SMC is confused.
I'd reset the SMC.

Unplug the battery, disconnect the power cord and hold down the power button for 5 seconds - reconnect everything up and see what happens.

Health is the condition of the battery - how much of a charge it is capable of holding compared to when it was new - system profiler will give you more detailed figures..
Charged is how much the battery is charged up.

[angelmb]

Thanks both of you, great input there. I know it sounds really weird but actually the number of cycles is correct, battery has never been fully discharged cause the MacBook Pro sits over the desk all the time, hence plugged into mains.

[seanc]

How long has it been sat on that desk? It's a good practice to discharge and re-charge it every month or so.

[Big Mac]

Apple Notebooks (Battery Recommendations)
"For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month. Need a reminder? Add an event to your desktop’s iCal."

[angelmb]

Originally Posted by seanc 

How long has it been sat on that desk? It's a good practice to discharge and re-charge it every month or so.

I bought it when it was released so I owe it some charge-discharge cycles… thing is the MBP gets little use really but even so I have to follow your recommendations (same goes for Big Mac's).

[seanc]

Yep you need to follow those guidelines - the battery doesn't stop because you stop using the MBP.

I'm totally in the dark about what MBP you have, for all I know its been there since 2006!

Why not sell it for something you'll use more?

[angelmb]

Oh, sorry I didn't mention it, I thought I had but I see I rewrote my original post and such mention was lost… It is the Unibody 15", so it is fairly new.

As for sell it, well, while the Mac Pro is my main computer, I still have the 24" aluminum iMac and my beloved Power Mac MDD… but it is the only Mac laptop I have and I kind of miss the fantastic experience I had with the PowerBook Pismo, so the Unibody shall get that role sooner than later.

[polendo]

happened to my iBook some time ago.. and the battery had a defect.. changed under warranty which in turned happened again. Coincidently it also stucked at 82%, BUT it kept charging forever.

[P]

There is an upper limit beyond which the battery will not charge. This is done intentionally, to cut down on the number of charge cycles "used up". Try unplugging the MBP and run it down below 50% and see what happens when you plug it in again.

[angelmb]

Interesting, will try that. Thanks.

[Simon]

The threshold for not charging is ~96%. It prevents minor but constant top-offs. So that's unrelated to the issue here.

Check what your full charge capacity is (in Sys Profiler). It should be ~82% of the original full charge capacity (4.6 Ah IIRC for the 15" unibody MBP). Having a battery stuck at 82% indicates something's wrong. Either with the SMC or with the battery itself. Here's what you do:

1) Reset SMC.
2) Recalibrate the battery.
3) If that doesn't help...
Once you're below 80% of your original full charge capacity, you can call up Apple and ask them to send you a replacement battery. If your battery has less than 300 cycles and is still within the original 12 month warranty period it should be able to hold 80% of its original full charge capacity (their spec). If it doesn't Apple will replace it for free.

That said, even if you plan on always having it plugged in, you should cycle it once in a while per Apple's instructions (as posted above) if you want it to last a bit. And just out of curiosity, if you're planning on using it plugged in all the time, why would you worry about battery stats anyway? With that usage pattern, the battery *will* suffer and eventually it will die. Like every other battery. Just a bit faster.

[angelmb]

System Profiler says capacity is 4434 mAh so I guess everything is OK… I am running it now unplugged to check if the consequent charge goes OK.

hey gossiplady, thank you for your spam-input too, I guess to watch some DVDs are a great way to drain the battery

[angelmb]

Battery went down to 4% and right now is at 96%. Seems to be working as expected.

[polendo]

I think Im going to try that with the iBook LOL!

[DCJ001]

I didn't see where anyone mentioned that the MacBook should be allowed to sleep/shut down for 5+ hours after the battery is drained for calibration. It's best to get the details straight from Apple:

Apple Portables: Calibrating your computer's battery for best performance

[angelmb]

Thanks for the link DCJ001, I appreciate that.

[DCJ001]

Originally Posted by angelmb 

Thanks for the link DCJ001, I appreciate that.

You're welcome.

[Simon]

I think it's worth pointing out that the proper calibration procedure is pointed out in every portable Mac's user manual in the first place. The KB article is basically a copy of that.

The simple discharge-recharge procedure isn't wrong, but outdated. Back in the pre-Intel days that's how Apple told people to calibrate their batteries. After the MBP came out the procedure changed a bit and now includes a 5h break once it's drained and a 2h connection to power once it's fully charged. These changes were (and still are) published by Apple in every manual. This is not some kind of insider trick or anything. It's the proper way to calibrate an Intel Mac per Apple.

[glowingcactus]

Long post but I am uncertain about what I should be doing with my new free battery.

I have owned 4 Mac laptops since 1999 (Lombard) all the way through to my current machine, an "early 2008 MacBookPro4.1", (with Leopard). All still work and all three older ones are used (as in handed down) by family members at home. All were used by myself in turn as a primary machine in pretty much the same manner running off mains when available. Yes the battery lives in the older ones is now not great but they all still hold charge and warn correctly when in need of charging. Except one. The newest one. On battery power the MacBookPro4.1 goes off without warning, no sleep, no shutdown, no save of RAM, just like a desktop in a power cut without a UPS. I thought it was a dead duck first time it happened out of the blue, and during a presentation too . System profile reported all the usual battery power stats with only the Status showing unusual readings 'check battery'.

I am not intending here to pick an argument. I Like Apple etc etc. I just curious if there is something fundamentaly wrong with all these recent Sony batteries even recent ones as there are an awful lot of failures it seems. Just look at the Battery forums in the official discussions. I am curious as to what is actually happening here.

For the first time I had to call upon Apple Care (yes lucky me) because the battery in the MBP (early 2008) conked out without warning at 80%. Recalibrating could not be done as it always failed. But thanks to the generosity of a Genius in assesing my case I got a free replacement pack. Thank you Apple Thank you Mr Genius.

I am concerned I will be in the same boat in 1 years time.

The machine is currently 1 year and 1 month old. The failed battery cycle was 30. Yes I realise that that is v.low but ALL my portable machines have low cycle counts and it has never caused me a problem in 10 years of PowerBook use. I figured that draining down once a fortnight would be sufficient for cycling the battery management to keep it healthy. Apparently not. So I wonder if once a week would that have been better? Cycle count would have been 60 or so. How about once every two days? But then the cycle count would be even higher and the genius may have regarded that as normal mortality and so no free battery. Confused as to what to do with this new battery. I have read the official recommendation on recalibrating and I am doing this now.

What was interesting was I was told by the Genius that 3 year Apple Care does not include batteries. Batteries are only covered for 12 months and are considered consumables and I was at 13months. However tests indicated (Mr Genius plugged in an iPod Nano into the MacBook Pro, booted off it and run a battery utility test, screen went red & I guess red is not good) to him that the circuit in the battery pack chip was not behaving correctly and this was covered by Apple Care and that means I get a free battery. So Good news for me.

But this is another curious point. What counts as "the battery"? To me the removable pack as a whole is "the battery". So if the chip inside had failed, to me that is a battery failure too In which case would that not = no free battery after 12 months.

However I think it may have been a cell in the pack that went but for some reason and Apple is dealing with some of these cases as if it was it the 'chip' that was not working. But What could causes it to fail?

Also why can't these battery management chips include a strategy to help the user protect the cells? Like an opt-in reminder scheme to cycle this pack in an optimal way. Right now it seems have to device a routine of my own to cycle the battery in an unknown balance of the number cycles count vs expected life vs dont leave it on charge once at 100%. Why can't the chip do that? Actually I though it would have done at least that.

Chances are that I won't choose the "correct" strategy and the battery failure will be my fault.

[ghporter]

Winding up with a battery that failed is not an indicator that another battery will fail in the same computer. In fact, you might think of it in the other direction; since you've already had a battery fail in that machine, the odds are very strong AGAINST another battery failure. Further, if you did have a second battery failure, Apple should start to suspect that there's something wrong with the computer, and perhaps check it out thoroughly. Either way, I would be anything but anxious about a second battery failure at this point.

"The battery" is the whole detachable package. It includes a number of rechargeable cells and a processor that monitors battery voltage and charge information, plus keeps track of things like number of cycles. The cells themselves are incredibly simple things, and they are indeed consumable. Their configuration in the battery is what determines voltage and current capacity, but individually they're quite simple. Since they're simple, and since they're produced in such huge quantities, cells can fail. Just flat out stop working. There are two ways they can fail: short or open. A shorted cell will reduce the voltage of the battery, while an open cell will basically kill the battery. It sounds like your "check battery" issue was an open cell. Interestingly, it might not even have been the cell that opened, but rather a connection at either end of the cell. Since Apple has replaced the battery for you, it really doesn't matter.

What the battery's processor does is tell the computer what's going on with the battery, and the computer gives the user that information via a few routes, including the interface that provides the data you get in System Profiler. It's up to the user to attend to the management of the battery because otherwise plenty of users would be upset that their computers decided some power management thing FOR them and it caused problems with X, Y or Z. You could set yourself a reminder (in iCal, for example) to cycle the battery regularly, which is probably the best, "most correct" strategy for ensuring long battery life.